Well, I kinda like the idea of having HWPs and their Turrets separated items... maybe as a Mod for Vanilla OpenXcom. That way we eliminate the need to buy new HWPs just for the different weapons. There are also new Chassis ideas I'd like to suggest just to have more late game options.
Tracked ChassisStrong damage resistance
Enhanced Tracked ChassisStrongest damage resistance
Walker ChassisStronger damage resistance / Increased TUs
Hover ChassisStronger damage resistance / Can Hover / Produces a small explosion when destroyed
This would mean some of the stats would depend on the weapon used. Also, the Turrets Rocket Launcher and Fusion Ball Launcher should have 0 points in Reaction. I'm thinking about adding more Chassis and Turret ideas.